The present invention relates in general to the detection of system faults and more particularly to the detection of anomalies in a physical system.
The maintenance and monitoring of physical systems, including complex systems like aircraft engines, rocket propulsion systems, and aerospace vehicles, is important for the prevention and detection of abnormal operating conditions. In particular, it is desired to detect operating conditions of the physical system that correspond to unknown fault modes, or simply anomalies.
Traditional approaches have not been effective in detecting certain types of faults or failures, especially the detection of anomalies in complex systems. The detection of anomalies is typically more difficult than the detection of known failure modes because the failure mode has not been previously identified or categorized. Some prior failure detection approaches are based on data-driven signal-processing that examines the statistical characteristics of measured data streams obtained from a system. However, these types of approaches are not well-suited to detecting anomalies of a system that experiences large variations in operating variables and frequent mode switching, and have only provided limited accuracy in detecting such anomalies. Further, these and other types of fault detection approaches have required significant amounts of domain expertise or physical knowledge about the system, thus increasing the cost and difficulty of detecting anomalies. Anomaly failure detection by such approaches is further complicated in complex systems due to the wide variation of operating conditions, especially when the system is not at steady-state.
Accordingly, there is a need for an improved way to detect anomalies in physical systems that reduces the extent of knowledge required about the system, that can handle failure modes that exceed the data parameter space collected about the prior operation of the system, and that can readily handle anomaly detection in the complicated operational modes observed in complex physical systems.